diff --git a/snakehouse/multibuild.py b/snakehouse/multibuild.py
index 52d998e3a4f084f555ff1bd40babdfc3ceb63b69..1f75124fcdc8c7dca4831006b52814f8ff9949b5 100644
--- a/snakehouse/multibuild.py
+++ b/snakehouse/multibuild.py
@@ -1,11 +1,15 @@
 import os
 import collections
 import typing as tp
+import logging
 import pkg_resources
 from satella.files import split
 from mako.template import Template
 from setuptools import Extension
 
+logger = logging.getLogger(__name__)
+
+
 CdefSection = collections.namedtuple('CdefSection', ('h_file_name', 'module_name'))
 GetDefinitionSection = collections.namedtuple('GetDefinitionSection', (
     'module_name', 'pyinit_name'
@@ -119,8 +123,10 @@ class Multibuild:
         self.alter_init()
 
     def for_cythonize(self, *args, **kwargs):
+        for_cythonize = [*self.files, os.path.join(self.bootstrap_directory, '__bootstrap__.pyx')]
+        logger.warning('For cythonize: %s', for_cythonize)
+
         return Extension(self.extension_name+".__bootstrap__",
-                         self.files + [os.path.join(self.bootstrap_directory,
-                                                    '__bootstrap__.pyx')],
+                         for_cythonize,
                          *args,
                          **kwargs)